WO2007131268A1 - Sonde hyperfréquence - Google Patents

Sonde hyperfréquence Download PDF

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Publication number
WO2007131268A1
WO2007131268A1 PCT/AU2007/000632 AU2007000632W WO2007131268A1 WO 2007131268 A1 WO2007131268 A1 WO 2007131268A1 AU 2007000632 W AU2007000632 W AU 2007000632W WO 2007131268 A1 WO2007131268 A1 WO 2007131268A1
Authority
WO
WIPO (PCT)
Prior art keywords
probe
antenna
transmit antenna
receive antenna
signals
Prior art date
Application number
PCT/AU2007/000632
Other languages
English (en)
Inventor
Garry France
Original Assignee
Callidan Instruments Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2006902650A external-priority patent/AU2006902650A0/en
Application filed by Callidan Instruments Pty Ltd filed Critical Callidan Instruments Pty Ltd
Priority to US12/300,048 priority Critical patent/US7982470B2/en
Publication of WO2007131268A1 publication Critical patent/WO2007131268A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N22/00—Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more
    • G01N22/04—Investigating moisture content

Definitions

  • This invention relates to a probe useful with a source of microwave signals to determine an amount of a component in a sample.
  • the invention relates to a microwave probe that can be used to determine an amount of a component in a sample by measuring the change in a microwave signal after transmission through the sample.
  • the invention is suitable for determining the amount of a component in a sample when the probe is immersed into a bulk amount of material.
  • Measurement of the properties of materials is traditionally carried out using conventional laboratory analysis of a manually collected sample. This process is expensive and time consuming, and results for different material batches may be easily confused due to the time taken between sampling and the receiving of results.
  • a device capable of delivering immediate results to the operator whilst in contact with the sample removes a large portion of potential errors and allows immediate decision making regarding the quality of said material due to its properties.
  • a microwave signal passes through the material, some of the signal is absorbed such that the amplitude (i.e. power level) of the received microwave signal is less than was transmitted.
  • the amount of attenuation may be directly related to the material property that is desired to be measured.
  • the velocity of the microwave signal is also affected by its passage through the material. This slowing of microwave velocity creates a phase shift in microwave signal.
  • a phase shift is time difference between when a signal is received compared to when it should have been received with no interference. Attenuation and phase shift may be used to infer a number of compositional properties about the material being analysed.
  • GB 2,122,741 describes an apparatus for monitoring crushed coal.
  • the apparatus monitors ash content and moisture content of the coal by respectively transmitting and detecting X-ray and microwave radiation.
  • the microwave radiation amplitude is chopped at a low frequency of about 1.OkHz, which is suitable for analysing a crushed sample such as coal.
  • This apparatus is not well suited for determining moisture content of other types of samples and is not easily portable.
  • US 4,788,853 describes a moisture meter that also uses microwave signals at discrete discontinuous frequencies. This patent states that the number of frequencies required to perform the invention is not critical as long as sufficient data is generated. The device is designed for use with material moving on a conveyor belt.
  • AU 61689/90 describes an apparatus for determining moisture content in a sample of varying thickness on a conveyor belt.
  • the microwave signals are also transmitted at discrete discontinuous frequencies within a selected range.
  • the invention resides in a probe comprising:
  • a transmit antenna disposed towards an end of the support member; a receive antenna disposed adjacent the transmit antenna; and a signal barrier disposed on the support member between the transmit antenna and the receive antenna so as to force signals traveling from the transmit antenna to the receive antenna to propagate through a surrounding region.
  • a sample analysis device comprising: a probe including a transmit antenna disposed towards an end of a support member;
  • a signal barrier disposed on the support member between the transmit antenna and the receive antenna so as to force signals traveling from the transmit antenna to the receive antenna to propagate through a surrounding region;
  • FIG 1 is a sectional side view of a first embodiment of a probe
  • FIG 2 is an end view of the probe of FIG 1 ;
  • FIG 3 is a side view of the probe of FIG 1 during operation
  • FIG 4 shows the range of possible dimensions of the probe
  • FIG 5 is a perspective view of a second embodiment of a probe
  • FIG 6 is an end view of the probe of FIG 5.
  • FIG 7 displays a plot of performance when measuring moisture content.
  • FIG 1 there is shown a schematic of a probe 1 consisting of a support member 2 with an antenna arrangement 3 towards one end.
  • the antenna arrangement 3 comprises a transmit antenna 4 and a receive antenna 5 separated by a barrier 6.
  • the transmit antenna 4 is a brass cylinder affixed near the end of the support member 2.
  • the receive antenna 5 is also a brass cylinder adjacent to the transmit antenna 4 but separated from the transmit antenna 4 by a barrier 6 composed of, for example, brass and/or microwave absorbing rubber.
  • microwave signals are carried to the transmit antenna 4 by coaxial cable 7.
  • the microwave signals emanate from the antenna 4 into surrounding material. After passing through the surrounding material, the microwave signals are received by the receive antenna 5 and carried by coaxial cable 8 for signal processing.
  • the coaxial cables 7, 8 are suitably seated in grooves formed along the length of the support member 2.
  • the support member 2 is formed of any suitable material.
  • the support member is formed as a rod of a stiff material such as brass, in which case insulation material 20 (see FIG 2) is located between the support member 2 and the antennas.
  • the insulation material is formed of any suitable material which does not conduct signals, such as plastic or ceramic. If the support member 2 is formed from a material which itself does not conduct microwave signals, eg Teflon, the insulation material 20 is not required and may be omitted. Although a stiff support rod is preferred there may be applications where a flexible rod is more appropriate.
  • the transmit antenna 4 and the receive antenna 5 may be manufactured from any material capable of conducting microwave signals, such as brass or copper.
  • the respective positions of the transmitting and receiving antennae are interchangeable, provided they are separated by barrier 6.
  • the barrier 6 may be manufactured from any material capable of blocking direct signal transmission between the transmit antenna 4 and the receive antenna 5.
  • the barrier is formed from brass and microwave absorbing rubber.
  • the barrier may also be formed from an insulating ceramic material or plastic. In this case the barrier may be formed integrally with the support member 2.
  • a microwave field generated by the probe 1 during operation is shown in FIG 3.
  • Microwave signals emanating from the transmit antenna 4 and received by the receive antenna 5 form a toroidal microwave field geometry 9. This field is formed because the barrier 6 prevents a direct path between the transmit antenna and the receive antenna.
  • the expanded microwave field is forced to traverse and interact with the surrounding material.
  • the resulting signal attenuation and phase shift of the received microwave signal is processed and used to infer any of a number of compositional properties of the test material. These properties include, but are not restricted to:
  • one or more properties may be measured simultaneously (ie concurrently) or in series by analyzing the received microwave signals accordingly.
  • the preferred operating frequency of the antenna configuration may be determined by a set of fundamental dimensions.
  • the fundamental dimensions of one embodiment of the antenna configuration are shown in FIG 4.
  • the fundamental dimensions of Table 1 allow the system to operate optimally between 0.1GHz and 20GHz.
  • FIG 5 there is shown a schematic of a second embodiment of the microwave probe 50 consisting of a support member 2 with an antenna arrangement 51 towards one end.
  • the antenna arrangement 51 comprises a transmit antenna of two brass lobes 52A and 52B and a receive antenna of two brass lobes 53A and 53B.
  • the transmitting antenna lobes are separated from the receiving antenna lobes by a barrier 6, as described above.
  • the geometry of the microwave field generated by the antenna arrangement is linear or part- toroidal as represented by 56 in FIG 6.
  • the arrangement, dimensions and shape of the antenna may be varied in order to provide a microwave field geometry that corresponds to the particular sample application.
  • a linear field, rather than toroidal, may be more suited for measurements in a sample with only a shallow depth.
  • Microwave signals are carried to both parts of the transmitting antenna 52A and 52B by coaxial cable 54 and returned for signal processing from both parts of the receiving antenna 53A and 53B by coaxial cable 55.
  • support member 2 is formed from a material capable of conducting microwave signals, insulation material will be required between the support rod and the antennae.
  • the probe of the first embodiment described above has been successfully demonstrated to accurately measure the moisture content in mono-ammonium phosphate (MAP) fertilizer.
  • Standard samples of the MAP fertilizer were created with specific moisture contents, which were independently confirmed.
  • a probe using an embodiment of the antenna design was immersed into the material, and the signal attenuation and phase shift were measured. These measurements were correlated against the moisture content of the samples. The results are presented in Table 2 and FIG 7.
  • the tabulated data is plotted in FIG 7.

Abstract

La présente invention concerne une sonde pour obtenir une mesure d'une ou plusieurs propriétés dans un échantillon; la sonde comprend un élément de soutien (2), une antenne de transmission (4), une antenne de réception (5) et une barrière signal (6). La barrière signal (6) est située entre l'antenne de transmission (4) et l'antenne de réception (5) afin d'obliger les signaux se déplaçant entre l'antenne de transmission (4) et l'antenne de réception (5) à se propager dans la région environnante. La modification du signal hyperfréquences près son passage dans la région environnante est mesurée et utilisée pour appliquer une ou plusieurs propriétés au matériau de test.
PCT/AU2007/000632 2006-05-17 2007-05-10 Sonde hyperfréquence WO2007131268A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/300,048 US7982470B2 (en) 2006-05-17 2007-05-10 Microwave probe device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AU2006902650A AU2006902650A0 (en) 2006-05-17 Microwave antenna
AU2006902650 2006-05-17
AU2007900430A AU2007900430A0 (en) 2007-01-30 Microwave antenna
AU2007900430 2007-01-30

Publications (1)

Publication Number Publication Date
WO2007131268A1 true WO2007131268A1 (fr) 2007-11-22

Family

ID=38693437

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2007/000632 WO2007131268A1 (fr) 2006-05-17 2007-05-10 Sonde hyperfréquence

Country Status (2)

Country Link
US (1) US7982470B2 (fr)
WO (1) WO2007131268A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008013391A1 (de) * 2008-03-10 2009-10-01 Krohne Meßtechnik GmbH & Co KG Verfahren und Einrichtung zur Messung dielektrischer Profile

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4788853A (en) * 1985-10-25 1988-12-06 Coal Industry (Patents) Limited Moisture meter
WO1991002966A1 (fr) * 1989-08-15 1991-03-07 Commonwealth Scientific And Industrial Research Organisation Determination de la teneur en humidite d'un produit par calcul du dephasage de micro-ondes et du rapport masse/surface
WO2003016887A2 (fr) * 2001-08-13 2003-02-27 Signature Bioscience, Inc. Procede d'analyse d'evenements cellulaires
JP2004101521A (ja) * 2002-08-22 2004-04-02 Nagoya Electric Works Co Ltd 路面における凍結防止剤の濃度計測方法およびその装置
US20040100280A1 (en) * 2002-11-27 2004-05-27 Tohoku Techno Arch Co., Ltd. Noncontact measuring system for electrical conductivity
US20050016683A1 (en) * 2003-07-23 2005-01-27 Korea Research Institute Of Standards And Science Plasma electron density measuring and monitoring device
US20060061371A1 (en) * 2002-10-30 2006-03-23 Toshifumi Inoue Probe for physical properties measurement
WO2006030060A1 (fr) * 2004-09-14 2006-03-23 Upm Rafsec Oy Agencement d'essai pour transpondeurs rfid

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4544880A (en) * 1982-04-28 1985-10-01 General Motors Corporation Microwave probe for measurement of dielectric constants
US4904928A (en) * 1988-12-09 1990-02-27 E. I. Du Pont De Nemours And Company Measurement apparatus and method utilizing multiple resonant modes of microwave energy
US7226446B1 (en) * 1999-05-04 2007-06-05 Dinesh Mody Surgical microwave ablation assembly

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4788853A (en) * 1985-10-25 1988-12-06 Coal Industry (Patents) Limited Moisture meter
WO1991002966A1 (fr) * 1989-08-15 1991-03-07 Commonwealth Scientific And Industrial Research Organisation Determination de la teneur en humidite d'un produit par calcul du dephasage de micro-ondes et du rapport masse/surface
WO2003016887A2 (fr) * 2001-08-13 2003-02-27 Signature Bioscience, Inc. Procede d'analyse d'evenements cellulaires
JP2004101521A (ja) * 2002-08-22 2004-04-02 Nagoya Electric Works Co Ltd 路面における凍結防止剤の濃度計測方法およびその装置
US20060061371A1 (en) * 2002-10-30 2006-03-23 Toshifumi Inoue Probe for physical properties measurement
US20040100280A1 (en) * 2002-11-27 2004-05-27 Tohoku Techno Arch Co., Ltd. Noncontact measuring system for electrical conductivity
US20050016683A1 (en) * 2003-07-23 2005-01-27 Korea Research Institute Of Standards And Science Plasma electron density measuring and monitoring device
WO2006030060A1 (fr) * 2004-09-14 2006-03-23 Upm Rafsec Oy Agencement d'essai pour transpondeurs rfid

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008013391A1 (de) * 2008-03-10 2009-10-01 Krohne Meßtechnik GmbH & Co KG Verfahren und Einrichtung zur Messung dielektrischer Profile
DE102008013391B4 (de) * 2008-03-10 2013-06-06 Krohne Meßtechnik GmbH & Co KG Verfahren und Einrichtung zur Messung dielektrischer Profile

Also Published As

Publication number Publication date
US20090195259A1 (en) 2009-08-06
US7982470B2 (en) 2011-07-19

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